This is an application to study tolerance induction by a peptide (12-26) epitope of a bacteriophage lambda protein fused at the N-terminus of an IgG heavy chain. Injection of the myeloma fusion protein or transduction of bone marrow cells with the gene for this fusion protein have both led to B-cell unresponsiveness in vivo. The investigators suggest that this system offers a novel approach for immunotherapy of autoimmune diseases.